A5072441433- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Conducting polymers and applications
- CO2 Reduction Techniques and Catalysts
- Analytical Chemistry and Sensors
- Electrodeposition and Electroless Coatings
- Carbon dioxide utilization in catalysis
- Molecular Junctions and Nanostructures
- Radical Photochemical Reactions
- Ionic liquids properties and applications
- Spectroscopy and Quantum Chemical Studies
- Ammonia Synthesis and Nitrogen Reduction
- Pigment Synthesis and Properties
- Spectroscopy Techniques in Biomedical and Chemical Research
- Oxidative Organic Chemistry Reactions
- Metallic Glasses and Amorphous Alloys
- Network Security and Intrusion Detection
- High Entropy Alloys Studies
- Bee Products Chemical Analysis
- Electrochemical sensors and biosensors
- Polymer crystallization and properties
- Nanopore and Nanochannel Transport Studies
- Advanced Malware Detection Techniques
- Information and Cyber Security
University of Utah
2020-2025
University of North Carolina at Chapel Hill
2018-2021
Creative approaches to the design of catalytic nanomaterials are necessary in achieving environmentally sustainable energy sources. Integrating dissimilar metals into a single nanoparticle (NP) offers unique avenue for customizing activity and maximizing surface area. Alloys containing five or more equimolar components with disordered, amorphous microstructure, referred as High-Entropy Metallic Glasses (HEMGs), provide tunable performance based on individual properties incorporated metals....
Alcohol oxidation is an important class of reaction that traditionally performed under harsh conditions and most often requires the use organometallic compounds or transition metal complexes as catalysts. Here, we introduce a new electrochemical synthetic method, referred to reductive oxidation, in which alcohol initiated by redox-mediated electrocatalytic reduction peroxydisulfate generate highly oxidizing sulfate radical anion. Thus, counter-intuitively, occurs result reaction. This...
Experimental electrochemistry offers unique opportunities for interactive instruction at all levels of education; however, widespread adoption in curricula is hindered by high costs associated with electrochemical instrumentation. Thus, the development affordable instruments represents an essential step toward making accessible to everyone. While numerous commercially available three-electrode potentiostats exist, two-electrode provide a simple and inexpensive alternative. Herein, we present...
Prodigious resources are currently being devoted to control the size and morphology of metal nanoparticles (NPs). Several homogeneous chemical photochemical techniques exist for synthesis NPs; however, these synthetic methods generally leave a distribution NP shapes sizes require stabilizing ligand prevent aggregation. Electrodeposition NPs onto conductive surfaces is versatile technique. However, spatial on surface difficult attain, even well-behaved materials like highly oriented pyrolytic...
The utility of transition metal hydride catalyzed hydrogen atom transfer (MHAT) has been widely demonstrated in organic transformations such as alkene isomerization and hydrofunctionalization reactions. However, the highly reactive nature radical intermediates hindered mechanistic insight into this pivotal reaction. Recent advances electrochemical MHAT have opened up possibility for new analytical approaches diagnosis. Here, we report a voltammetric interrogation Co-based reactivity,...
Crystallization from the melt is a critical process governing properties of semi-crystalline polymeric materials. While structural analyses melting and crystallization transitions in bulk polymers have been widely reported, contrast, those thin polymer films on solid supports underexplored. Herein, situ Raman microscopy self-modeling curve resolution (SMCR) analysis are applied to investigate temperature-dependent changes poly(ethylene oxide) (PEO) during phase transitions. By resolving...
We demonstrate quantification of porosity, nanopore tortuosity, and electrical connectivity at the single-nanoparticle (NP) level for NPs synthesized by nanodroplet-mediated electrodeposition. Focused ion beam nanoslice tomography was used to slice with ca. 10 nm resolution followed imaging using scanning electron microscopy (SEM), allowing measurement these parameters on not amenable transmission microscopy. Slices were reconstructed in three dimensions revealed pores an average size 3 ± 2...
We present a robust and facile method to produce metal nanoparticle (NP) alloys in one-step synthesis using direct electrodeposition onto highly oriented pyrolytic graphite (HOPG). Precursor salts, H2PtCl6 Pd(NO3)2, were dissolved 1 mM sodium dodecylsulfate (SDS) water droplet with 1× phosphate buffered saline solution suspended dichloroethane (DCE) continuous phase. Tetrabutylammonium perchlorate was added the DCE phase maintain charge balance during electrodeposition. NP fabrication via...
Proton transfer at solid/liquid interfaces is a fundamental step in many complex biological and electrocatalytic processes. Previous model studies using electrodes modified with self-assembled monolayers (SAMs) of carboxylic acid-terminated alkanethiols have demonstrated that interfacial proton controlled by the local electrochemical microenvironment. The thermodynamic driving force for electrochemically driven protonation/deprotonation acid/base SAMs governed combination electric potential...
Nanoparticles interact with a variety of interfaces, from cell walls for medicinal applications to conductive interfaces energy storage and conversion applications. Unfortunately, quantifying dynamic changes nanoparticles near is difficult. While optical techniques exist study nanoparticle dynamics, motions smaller than the diffraction limit are difficult quantify. Single-entity electrochemistry has high sensitivity, but technique suffers ambiguity in entity's size, morphology, collision...
Single-entity electrochemistry has emerged as a powerful tool to study the adsorption behavior of single nanoscale entities one-at-a-time on an ultramicroelectrode surface. Classical single-entity collision studies have focused spherical nanoparticles or where orientation colliding entity does not impact electrochemical response. Here, we report detailed asymmetric graphene nanoplatelets onto ultramicroelectrodes. The conductive biased surfaces can be observed in amperometric i–t trace,...
Copper nanoparticles have emerged as promising electrocatalysts for energy storage and conversion.
The electrical double layer (EDL) can lead to unexpected voltammetric phenomena. A notable example is the Frumkin effect, observed for reduction of peroxydisulfate (S2O82–). In absence excess supporting electrolyte, rate S2O82– decreases as cathodic overpotential increased, contrary expectations faradaic electron-transfer processes. Here, we report a demonstration effect at Hg ultramicroelectrodes, revealing steady-state voltammetry behavior consistent with prior observations rotating disk...
The utility of transition metal hydride catalyzed hydrogen atom transfer (MHAT) has been widely demonstrated in organic transformations such as alkene isomerization and hydrofunctionalization reactions. However, the highly reactive nature radical intermediates hindered mechanistic insight into this pivotal reaction. Recent advances electrochemical MHAT have opened possibility for new analytical approaches diagnosis. Here, we report a voltammetric interrogation Co-based reactivity, describing...
A mechanism for the concerted pathway of coupled electron- and phase-transfer reactions (CEPhT) is proposed. CEPhT at three-phase interfaces formed by a solid electrode, an insulating organic solvent, aqueous electrolyte driven electric double layer (EDL) spillover, with significant electrostatic potential gradients extending few nanometers into phase. This EDL spillover phenomenon studied using scanning electrochemical cell microscopy to interrogate oxidation ferrocene in toluene...
The direct, transition metal-catalyzed carboxylation of organohalides with carbon dioxide is a highly desirable transformation in organic synthesis as it utilizes feedstock chemicals and delivers carboxylic acids –among the most utilized class molecules. Phenyl acetic acids, particular, are privileged motifs that appear many pharmaceuticals biologically active compounds. This article reports development sustainable selective cobalt-catalyzed electrochemical benzyl halides CO2 to generate...
2020 Edward G. Weston Summer Research Fellowship – Summary Report
The direct, transition metal-catalyzed carboxylation of organohalides with carbon dioxide is a highly desirable transformation in organic synthesis as it utilizes feedstock chemicals and delivers carboxylic acids –among the most utilized class molecules. Phenyl acetic acids, particular, are privileged motifs that appear many pharmaceuticals biologically active compounds. This article reports development sustainable selective cobalt-catalyzed electrochemical benzyl halides CO2 to generate...